Mixed layer depths from R/V Tangaroa cruise 61TG_3052 in the Southern Ocean in 1999 (SOIREE project)

• Main Authors: Dr Edward Abraham, Doug Mackie
• Format: Dataset
• Language: unknown
• Published: Biological and Chemical Oceanography Data Management Office (BCO-DMO) 2009
• Subjects: oceans; Southern Ocean
• Online Access: https://search.dataone.org/view/sha256:1246395d43910e784b0d518d88d54655af80fa9a32b599ff31c21a8125b10f0e

SOIREE Mixed Layer Depth<br> The mixed-layer depth is defined as the maximum depth at which the sea-water<br> density is less than the density at 5m + 0.1 kg m-3. This picks up the top of<br> the seasonal pycnocline, but is insensitive to the weaker stratification that<br> occurred during the latter part of the experiment.<br><br> There is considerable cast-to-cast variation, suggesting the presence of internal<br> waves. Despite this it appears that the average mixed-layer depth decreased by 5-10m<br> between the 9th and the 16th of February, and then shoaled by a similar amount during<br> the remainder of the experiment. The apparent rapid decrease between the 8th and the<br> 9th of February is possibly due to the inclusion of CTD stations on the transect towards<br> the experimental site, and may just reflect the general northward deepening of the surface<br> layer.<br><br> The development of thermal stratification within the surface layer is visible from Day 5.<br> This stratification is an order of magnitude weaker than the stratification within the pycnocline<br><br> <i><b>Comments preserved from the original file:</b><br> Defined as the maximum depth at which the density is less than the density at 5m + 0.1 kg/m3.<br><br> Casts where the mixed layer depth is undefined, either due to bad data or because the<br> cast was too short, are assigned a value of -1.<br><br> This depth is typically at the top of the seasonal pycnocline. During the latter part of the<br> experiment there was persistent weak stratification at shallower depths.<br><br> The upcast column is 0 for downcasts and 1 for upcasts.<br><br> </i>